The present application relates generally to semiconductor devices and includes methods and structures for improving hole structures.
An important capability for manufacturing reliable integrated circuits is to precisely shape the individual structures that form the integrated circuits. One such structure is a contact hole. Integrated circuits may comprise multiple layers, and contact holes are implemented between each layer to allow electrical communication between neighboring layers. Conventional integrated circuits may use millions of contact holes with a precise uniform width or critical dimension (CD).
The contact holes may provide a connection to an interface region that reduces contact resistance such as a Co-silicide. Etching processes may remove material from the interface region or punch through it completely resulting in increased contact resistance. The etching processes may also reduce a critical dimension (CD) of the contact holes' opening which may also increase contact resistance.
It would be desirable to form structures such as contact holes with improved characteristics to provide, for example, better contact performance.